Fig. 6

Knockdown of zdia2 inhibits epiboly cell migration by inhibiting cell protrusion formation.

Embryos injected with the standard control MO (stdMO) or the zdia2 splice-blocking MO (sMO) were dechorionated, immobilized, monitored, and recorded on 20-minutes continuous time-lapse movies (See supplement movie S1 and S2 for the stdMO and sMO-injected embryo, respectively). Photographs from each recording at 5-minutes intervals are shown in (A) with the recording time given in the lower right corner. All photographs are positioned with animal pole up. In the magnified pictures, marginal deep cells of the stdMO-injected embryo (B) exhibited clear protrusive activity with two protruded cell processes indicated by arrowheads, but no such protrusions were evident in the zdia2 sMO-treated embryo (C). Bars indicate 100 μm. (D) Cell protrusions formation at the leading edge of marginal deep cells in both stdMO- and zdia2 sMO-injected embryos were quantified separately by counting protrusions formed within the first 50 frames form 3 different movies, respectively. Results were then analyzed and only upper error bars of standard deviations are shown. Different letters on top of each column indicate a significant difference between treatments (P<0.05).